Add gitlab CI file.

This is a merged commit of a bunch of typos and whatnot.

.gitlab-ci.yml

+# This file is a template, and might need editing before it works on your project.
+# To contribute improvements to CI/CD templates, please follow the Development guide at:
+# https://docs.gitlab.com/ee/development/cicd/templates.html
+# This specific template is located at:
+# https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Getting-Started.gitlab-ci.yml
+
+# This is a sample GitLab CI/CD configuration file that should run without any modifications.
+# It demonstrates a basic 3 stage CI/CD pipeline. Instead of real tests or scripts,
+# it uses echo commands to simulate the pipeline execution.
+#
+# A pipeline is composed of independent jobs that run scripts, grouped into stages.
+# Stages run in sequential order, but jobs within stages run in parallel.
+#
+# For more information, see: https://docs.gitlab.com/ee/ci/yaml/README.html#stages
+
+image: ${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/alpine:latest
+
+stages:          # List of stages for jobs, and their order of execution
+  - build
+  - test
+  - deploy
+
+build-job:       # This job runs in the build stage, which runs first.
+  stage: build
+  script:
+    - apk update && apk --update add g++ build-base cmake bash libstdc++
+    - mkdir build && cd build
+    - cmake ..
+    - make
+
+unit-test-job:   # This job runs in the test stage.
+  stage: test    # It only starts when the job in the build stage completes successfully.
+  script:
+    - apk update && apk --update add g++ build-base cmake bash libstdc++ clang-tidy
+    - mkdir build && cd build
+    - cmake .. && make # TODO cache build from previous step
+    - ./tests/testfggl/fggl_test
+
+#lint-test-job:   # This job also runs in the test stage.
+#  stage: test    # It can run at the same time as unit-test-job (in parallel).
+#  script:
+#    - echo "Linting code... This will take about 10 seconds."
+#    - sleep 10
+#    - echo "No lint issues found."